Inductively Coupled Plasma Source Using Internal Multiple U‐Type Antenna for Ultra Large‐Area Plasma Processing

An inductively coupled plasma source with internal‐type linear inductive antennas named as “internal multiple U‐type antenna” was developed for the substrate size of 2 300 × 2 000 mm 2 and the characteristics of the large‐area inductive plasma source were investigated. High density plasmas on the order of 1.18 × 10 11 cm −3 could be obtained at the pressure of 15 mTorr Ar gas and the RF power of 8 kW with good plasma stability. In addition, by using variable capacitors at the end of the antenna, lower antenna voltage and more uniform antenna voltage distribution could be obtained. When a photoresist film was etched using O 2 plasma with 8 kW RF power, an etch uniformity less than 11% could be obtained using the multiple U‐type antenna on the substrate size larger than 7th generation (2 200 × 1 870 mm 2 ).